Surface coating, surface inclusion and other defects can be removed locally from the surface of the deposited layer before galvanized, which can be found and treated by conventional techniques. Excess foam is caused by the introduction of soap and saponable fatty surfactants into the tank. Moderate foam formation rates may be harmless. The presence of a large number of tiny homogenous particles in the tank, which can stabilize the foam layer, mat with activated carbon to remove surface active substances, or make the foam less stable through filtration, are effective measures.
